Dynamic response and damage evolution of Zr_(70)Cu_(13)Ni_(9.8)Al_(3.6)Nb_(3.4)Y_(0.2) bulk metallic glass(Zr-based BMG)under impact pressure ranging from 4.03 GPa to 27.22 GPa were studied.The Hugoniot Elastic Limit(...Dynamic response and damage evolution of Zr_(70)Cu_(13)Ni_(9.8)Al_(3.6)Nb_(3.4)Y_(0.2) bulk metallic glass(Zr-based BMG)under impact pressure ranging from 4.03 GPa to 27.22 GPa were studied.The Hugoniot Elastic Limit(HEL)and the spalling Strength(σ_(sp))were measured as 7.09 GPa and 2.28 GPa,and the curve of impact velocity(D)and particle velocity(u)were also obtained.Under the strain rate of~10^(5)s^(-1),local crystallization phenomenon was observed.As increasing the impact pressure,the failure mode of Zr-based BMG changed from spallation to fragmentation caused by the combination of spalling cracks and longitudinal cracks.Cone-cup structures were also observed in the internal spalling zone via nano-CT characterization.When increasing the impact pressure,the thickness of Zr-based BMG increased after impact and the remelting and cladding layers were also observed on the fracture surfaces.The fragments of the specimen were welded after impact due to the high temperature remelting,which causes plastic deformation of Zr-based BMG under shock loading.展开更多
Shock wave is associated with dynamic loading that can result in phase transition(PT), optical and mechanical property changing, and chemical reaction on materials. Here, we report recent progress about shockinduced P...Shock wave is associated with dynamic loading that can result in phase transition(PT), optical and mechanical property changing, and chemical reaction on materials. Here, we report recent progress about shockinduced PT of polycrystalline iron, the underlying mechanism of the optical emission from sapphire, and the synthesis from single-phase Ru Si in the National Key Laboratory of Shock Wave and Detonation Physics.Results indicated that grain boundary(GB) could affect the PT pressure threshold and rate of iron, the pressure threshold decreases with decreasing GB defects, and the PT rate shows a variation with increasing GB size; wavelength-dependent optical emissivity(non-gray-body emission) would be generated that was not revealed previously for shocked sapphire, and the observed luminescence was from the shock-induced shear bands, but without superheating phenomenon; shock compression could be an effective way to synthesis Ru-Si nanocrystals, when the shock pressure was appropriate; and Ru-Si powder could completely transform to fine-grain structure Cs Cl-type RuSi at 40.4 GPa.展开更多
文摘Dynamic response and damage evolution of Zr_(70)Cu_(13)Ni_(9.8)Al_(3.6)Nb_(3.4)Y_(0.2) bulk metallic glass(Zr-based BMG)under impact pressure ranging from 4.03 GPa to 27.22 GPa were studied.The Hugoniot Elastic Limit(HEL)and the spalling Strength(σ_(sp))were measured as 7.09 GPa and 2.28 GPa,and the curve of impact velocity(D)and particle velocity(u)were also obtained.Under the strain rate of~10^(5)s^(-1),local crystallization phenomenon was observed.As increasing the impact pressure,the failure mode of Zr-based BMG changed from spallation to fragmentation caused by the combination of spalling cracks and longitudinal cracks.Cone-cup structures were also observed in the internal spalling zone via nano-CT characterization.When increasing the impact pressure,the thickness of Zr-based BMG increased after impact and the remelting and cladding layers were also observed on the fracture surfaces.The fragments of the specimen were welded after impact due to the high temperature remelting,which causes plastic deformation of Zr-based BMG under shock loading.
基金partially supported by the National Natural Science Foundation of China(U1230202,11072227and 11272294)the Foundation of National Key Laboratory of Shock Wave and Detonation Physics(9140C670302130C67239)the Science and Technology Foundation of China Academy of Engineering Physics(2012A0201007)
文摘Shock wave is associated with dynamic loading that can result in phase transition(PT), optical and mechanical property changing, and chemical reaction on materials. Here, we report recent progress about shockinduced PT of polycrystalline iron, the underlying mechanism of the optical emission from sapphire, and the synthesis from single-phase Ru Si in the National Key Laboratory of Shock Wave and Detonation Physics.Results indicated that grain boundary(GB) could affect the PT pressure threshold and rate of iron, the pressure threshold decreases with decreasing GB defects, and the PT rate shows a variation with increasing GB size; wavelength-dependent optical emissivity(non-gray-body emission) would be generated that was not revealed previously for shocked sapphire, and the observed luminescence was from the shock-induced shear bands, but without superheating phenomenon; shock compression could be an effective way to synthesis Ru-Si nanocrystals, when the shock pressure was appropriate; and Ru-Si powder could completely transform to fine-grain structure Cs Cl-type RuSi at 40.4 GPa.
